During the nine and a half months of the year when they're out of season, I would pay anything for one delicious, ripe, homegrown tomato. In season, however, tomato values plummet faster than the euro. The cost of growing one yourself can fluctuate almost as much:

Above: The $85 tomato. This beauty was produced with the help of a tomato plant ($5), soil mix ($10), plant food ($5), insecticide ($15) and an Earth Box planter ($50). Image by Shutter, via Flickr. And now, a far less expensive alternative:

Above: The $9 tomato. Grown from seed, in a biodegradable pot, in an organic soil mix and with homemade fertilizer and pesticide. Image by Meytav Katzir, via Flickr.

Above: Start your seedling in a biodegradable Jiffy Pot (£0.20 from Greenfinger). For US gardeners, Jiffy Peat Pots are $1 apiece at Greenhouse. Transplant your seedling in one of those many empty terracotta pots you have lying around.

Above: For a recipe for homemade tomato fertilizer, made from ingredients like eggshells, visit My Pet Chicken. Image via Thermoforming.